Work through the following assignment exercises using the data sets provided. Prepare your answers using a word processing software such as Word. The answers should be provided as separateresearch reports that are each 2 to 3 pages long, with an additional page including your R scripts as an appendix. Convert the Word fifiles into a single PDF fifile and submit the latter through the LMS by the due date. The marking guide is provided in the appendix. If you have questions about this assignment, post them on the discussion board as those questions could be relevant to other students as well, and we want to ensure that all students get similar advice.
DUE DATE: Check LMS for due date and time.
You have been asked to investigate how the price of diamond depends on the attributes of the diamond (carat, colour, clarity) and the certifification body. Conduct an investigation of the hypothesis that price depends on the variables listed above and present your results in a structured report written in the IMRD format (see appendix). Your report should include the following: a statement of the research problem and the purpose of the analysis; a formal statement of the hypotheses; the methods and data used; a summary of the data; appropriate data plots
(a box plot of productivity growth against time, dot plots or plots of regression curves) ; a summary of the results from the analysis, including results from tests on alternative functional forms, and the main results on whether and how productivity growth has changed over time; an interpretation and discussion of the results; and a brief conclusion to fifinish the report.
(a) A statement of the research problem and the purpose of the analysis, and a formal statement of the null hypotheses you are testing.
(b) A description of the methods and data used, and a summary table of the data (including means, medians, standard deviations, etc. for numerical variables and proportions for categorical variables) and your observations about the data set.
(c) An appropriate graphical representation of the data, together with plots of the the regression lines you estimated. Do not clutter your plot by adding too many regression lines; two regression lines would be suffiffifficient – one for a basic model (e.g. a linear model) and another for a model that you have estimated as an improvement over the basic model (e.g. a nonlinear model with slope and/or intercept shifters that explains the data better).
(d) A discussion of whether a simple linear functional form is appropriate for describing the relationship between price and diamond attributes, including those described using cate gorical variables such as colour and clarity. Regression model selection should include a test of the functional form using RESET tests.
(e) Regression model results from your basic model and your best model presented in a table.
The results should be interpreted and discussed in the report. Discussion and interpretation should focus on improved regression but references should be made to basic model for comparison. The discussion should include a summary of why you think your second model is better suited for describing the variation in diamond prices.
(f) A brief conclusion to fifinish the report
Date source: SCIE4401 Faraway Diamonds Data
mark weight: 50%
The data fifile AgProductivity Sem2 2021.csv has information on environmentally-adjusted mul-tifactor productivity growth rates (%) for 17 countries over the period from 1991 and 2013.
The productivity growth rate is in the Value column; t is the time trend variable obtained by subtracting 1990 from the Year variable; COU is the country code; and Country is the country name.
Use the data provided to develop a regression model that would help determine if productivity growth rates can be explained as a function of time (time trend) and whether there is evidence that productivity growth rates have tended to decline over time. Your investigation should be structured and result in a report that follows the IMRD format. The report should include: a statement of the research problem and the purpose of the analysis; a formal statement of the hypotheses; the methods and data used; a summary of the data; appropriate data plots(a box plot of productivity growth against time, dot plots or plots of regression curves) ; a summary of the results from the analysis, including results from tests on alternative functional forms, and the main results on whether and how productivity growth has changed over time; an interpretation and discussion of the results; and a brief conclusion to fifinish the report.
Note that the underlying growth rates for difffferent countries will be difffferent and it would be necessary to use intercept shifters (country dummy variables) to accommodate these difffferences in the regression model. Another issue you need to decide on is whether the effffect of time on productivity growth is to be assumed to be the same or difffferent across difffferent countries.
In your report, you should include not only the model that you select as best but also one or more models that you estimated for comparison purposes (See yield regression exercise from week 11 for an example of a table reporting results from more than one model).
Date source: OECD Agricultural Productivity Data Archive
mark weight: 50%
A1: APPENDIX – IMRD Report & mark allocation
A report with an IMRD or IMRaD structure uses four sections to organise its content.
Introduction – What is the motivation for your research/analysis? (mark weight: 10%)
This section describes what the research is about, and why it is important or necessary. Re search can be important for scientifific and socioeconomic reasons (Scientifific and Socioeconomic signifificance). Demonstrating scientifific signifificance or importance requires showing that there is a research ”gap” that your research would fifill. Showing socioeconomic signifificance requires describing how the knowledge gained from the research will help improve decision making, man agement or policy solutions to problems. In simple cases, like short assignment exercises, the statement of the research problem and its signifificance can be based on a simple paraphrasing of the instructions for the exercise.
Methods and Data – What did you do and how? (mark weight: 20%)
This section describes the statistical methods and steps used to conduct the analysis as well as a description of the data used and their sources. The description should be clear enough for any other research to be able to replicate your results. Therefore, in your report, state clearly what methods you employed and in what order. And in the R script that you attach as an appendix, these steps should be clear and described using comments in the script.
Results – What did you fifind? (mark weight: 40%)
This section presents the fifindings, using text, fifigures and tables. Commentary or explanation should be reserved for the next section, but there could be minimal commentary in this section to indicate, for example, whether the null hypothesis is reject or not and why, etc. Follow style guides for fifigures and tables.
Discussion – What do the results mean? (mark weight: 15%)
This section summarises your main fifindings, comments on the fifindings, and relates or connects the fifindings to body of background knowledge or literature, and indicates what the implications of the results are for further research and for management/policy. This is also the section where you would indicate the limitations of your study (data or methods) so that future research can do a better job. (Note that in the case of assignment exercises like this, you are not required to do background research and thus you are not expected to relate your results to others’ fifindings.)
Overall presentation quality: The report should be systematically arranged and easy to read, well formatted, and free of typographical, grammatical and mechanical errors. (mark weight: 15%)